This invention relates to thermoplastic films for packaging applications, and more particularly relates to multilayer films which are machinable and have superior ink adhesion properties.
Thermoplastic film, and especially polyolefin materials, have been used in the past to package various articles including perishable food products which require resistance to physical and environmental abuse during storage and distribution, and an aesthetic and attractive appearance. Machinability of the film is required for it to be useful in the automated, relatively high speed production of multiple packages. Good shrink characteristics are necessary to produce a tight package appearance. Memory or package tightness retention is a measure of how well the packages then maintain the initial tight appearance. Such characteristic is important because packages typically must endure a distribution cycle which may range from a few days to a few weeks prior to being viewed by the final consumer. Ink adhesion is a measure of the printability of the film and is important for any printed package.
In the past a film useful in the packaging of poultry as well as other products and having excellent physical properties including good machinability, shrink and memory properties has been commercially available as SSD 310 film from Cryovac Division of W. R. Grace & Co.-Conn. However, there exists a need for a film having improved ink adhesion properties as compared to this commercial film.
The present invention meets this need with a multilayer film which provides adequate machinability, shrink, optics, and memory properties, while also providing improved ink adhesion properties.